Political trust is considered to be of crucial importance for the stability of democratic political regimes, and as such the concept is widely used in empirical research. In this paper I investigate the validity of the ‘institutional trust’-scale. Trust in political institutions has been studied as a one-dimensional as well as a multidimensional concept. On the one hand it has been argued that citizens use different criteria to evaluate the trustworthiness of different institutions (Fisher et al 2010; Hibbing and Theiss-Morse 1995). As citizens develop distinct trust judgements, one should not simply add these different trust judgments into one measurement scale. On the other hand institutions do not operate in a vacuum but they are all part of a political system with a particular prevailing political culture (Almond and Verba 1963). As a result, we can expect that citizens develop one comprehensive attitude ‘trust in political institutions’ which is shaped by the political culture of their country. Using factor analysis, I investigate the validity of a one-factor measurement model of institutional trust. The results are based on the European Social Survey 2008 (22 European countries, n=39,764.). The findings show that citizens have one comprehensive attitude ‘trust in political institutions’ which influences their trust judgement of various political institutions, providing strong support for the claim that political trust reflects an assessment of the prevailing political culture in a country. The results of a survey conducted among first-year Belgian university students in September 2010 (n=434) shows that even when the different trust judgements are not in the same battery institutional trust is one-dimensional. Using the Belgian student survey, I analyse how this institutional trust-scale relates to two other frequently used measures of political trust: satisfaction with democracy and the five ANES ‘trust in government’-questions. Finally I explore how these students come to their trust judgment by examining the expectations they hold towards these institutions. These findings will be used to arrive at a better understanding of the theoretical status of the notion of political trust.
